Proposal: attributes on type parameters

[hez2010]

Attributes on type parameters

Proposal

Allow attributes on type parameters.

Usage

public async Task<ValueTuple<bool, [MaybeNull]T> GetAsync<T>();

note:
It's not

public async Task<ValueTuple<bool, T> GetAsync<[MaybeNull]T>();

[Joe4evr]

This already works.

[hez2010]

@Joe4evr thanks! However [MaybeNull] could not be used on GenericParameter

[Joe4evr]

Oh, I see what you're doing now. You can only apply attributes on generic parameters at the place where the type is declared, meaning you'd have to own it. But even that won't help for a nested generic argument like this.

This is quite a conundrum. Pinging @jcouv for insight.